In the context of the topic at hand - this game show - you are incorrect.
The game has rules, and the contestants are specifically briefed on them prior to each game that they must enunciate all their words clearly and loud enough to be heard. In this case...the contestant simply blew it. It's not the first time, nor will it be the last.
Exactly... they have specific enunciation requirements on the show because of the kind of puzzles and the nature of the game. Sometimes they are using slang and wouldn't have a "G" at the end and someone would be buzzed wrong if they pronounced a G that wasn't there.
The rules are meant to try and guide people to pronounce only what is in the puzzle to be sure the contestant really solves the puzzle and they don't just think he did. Clarity and enunciation are key in the game.
IF you ask for an "M" be sure they know you mean "M" and not "N"... same for "B" and "D"... be clear so they give you the letter you ask for... same goes for solving the puzzle. The contestants are briefed I'm sure on those rules.